Chapter 6 pedigree

Genetics exam 3

Consanguinity

incest

Rareness or “rare”

anyone marrying into a family is not a carrier

Traits of Autosomal Recessive

• Approximately ¼ of all children affected

• can skip generations

• Affects males and females equally

Traits of Autosomal Dominant

• Both sexes transmit trait

• can’t skip generations

• affected child has affected parent (unless mutation is spontaneous

• Unaffected parents don’t transmit the trait

X-linked recessive traits

• Affected sons born from unaffected (heterozygous mothers)

  • affected males pass allele to all daughters

X-linked Dominant Traits

• Both males and females affected (usually more females than males)

• Affected sons must have an affected mother

  • Affects daughters have affected mother OR father

Y-linked traits

Every male has it